Field of the Invention
The present invention relates to an electronic device with a backlit display and an illuminated receptacle for a removable information storage medium, for example an audio device such as a cassette radio for a motor vehicle passenger compartment.
Electronic devices often have a combination of a backlit display, such as a liquid crystal display, and a receptacle for a removable information storage medium, such as an audio cassette. In many situations, for example in a motor vehicle passenger compartment, it may be difficult for a user readily to locate the entrance to the receptacle, particularly if this is covered over with a flap or door prior to insertion of the information carrier. One known way of indicating the location of the doorway is to provide a light source, for example a light emitting diode (LED), in close proximity with the entrance, so that light from the LED illuminates a part of the entrance so that it can more easily be located. In one conventional arrangement, the LED abuts a transparent light pipe that runs along the length of a doorway.
As regards the display, in one arrangement known from a motor vehicle cassette radio, a display is held on a display carrier on which LEDs are mounted for backlighting the display. A transmissive diffuser, such as frosted clear plastic material, is sometimes provided so that the light is more evenly distributed across the display.
The display LEDs may be mounted on a printed circuit board, on which the display and optionally a diffuser may be clipped or otherwise held. The same circuit board may hold another LED used to feed light into the light pipe to illuminate the entrance to the receptacle.
Whilst such arrangements are effective in providing the desired optical effects, two separate optical components must be provided; one for the display backlight and one of the entrance illumination. Therefore, it is generally necessary for a number of components such as a display carrier, optical light pipes or diffusers, and one or more PCBs to be fixed in place, usually by means of screws to the inner surface of a display or instrument bezel, which may then in turn be clipped to a chassis of the electronic device. This number of separate items and manufacturing steps adds to the cost of the audio device.
Furthermore, in order to benefit from the use of a single PCB, it is necessary for these components to be held in alignment with each other and the display and receptacle entrance. Particularly with moulded plastics components, this places tight tolerances on components' dimensions, which again adds to manufacturing cost.
It would be desireable to provide a more convenient arrangement for an electronic device having a backlit display and illuminated receptacle for a removable information storage medium.